ARM: OMAP2+: HDQ1W: add custom reset function

Implement a custom reset function for the HDQ1W IP block.  This is
because the HDQ1W IP block, like I2C, has an internal clock gating bit
that needs to be toggled after setting the SOFTRESET bit to allow the
reset to propagate.

Signed-off-by: Paul Walmsley <paul@pwsan.com>
Cc: NeilBrown <neilb@suse.de>
Cc: Avinash.H.M <avinashhm@ti.com>
Tested-by: NeilBrown <neilb@suse.de>